Department of Marketing, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
Nutrients. 2022 Nov 3;14(21):4649. doi: 10.3390/nu14214649.
The main barrier to the publication of observational research is a perceived inferiority to randomised designs with regard to the reliability of their conclusions. This commentary addresses this issue and makes a set of recommendations. It analyses the issue of research reliability in detail and fully describes the three sources of research unreliability (certainty, risk and uncertainty). Two of these (certainty and uncertainty) are not adequately addressed in most research texts. It establishes that randomised designs are vulnerable as observation studies to these two sources of unreliability, and are therefore not automatically superior to observational research in all research situations. Two key principles for reducing research unreliability are taken from R.A. Fisher's early work on agricultural research. These principles and their application are described in detail. The principles are then developed into four key principles that observational researchers should follow when they are designing observational research exercises in nutrition. It notes that there is an optimal sample size for any particular research exercise that should not be exceeded. It concludes that best practice in observational research is to replicate this optimal sized observational exercise multiple times in order to establish reliability and credibility.
观察性研究发表的主要障碍是，与随机设计相比，人们认为其结论的可靠性较低。本评论针对这一问题提出了一系列建议。它详细分析了研究可靠性问题，并充分描述了研究不可靠性的三个来源（确定性、风险和不确定性）。其中两个（确定性和不确定性）在大多数研究文献中没有得到充分阐述。它确定了随机设计与观察性研究一样容易受到这两个不可靠性来源的影响，因此在所有研究情况下并不自动优于观察性研究。从 R.A. Fisher 早期的农业研究中提取了两个降低研究不可靠性的关键原则。详细描述了这些原则及其应用。然后将这些原则发展为四项关键原则，观察性研究人员在设计营养观察性研究时应遵循这些原则。它指出，对于任何特定的研究，都有一个最佳的样本量，不应超过这个最佳量。它的结论是，观察性研究的最佳实践是多次重复这种最佳规模的观察性研究，以建立可靠性和可信度。
